Manufacture of moistureproof craped paper



PATENT OFFICE.

0F BOSTON, MASSACHUSETTS, A CORPORATION OIF MASSACHUSETTS.

meNUFAcTU-RE or Moisrunnrisoor cnernn renna.

Leaders.

Application led July 17,

To all whom it may concer/1t Be it known that I, ANDREW E. CURRIER, acitizen of the United-States, and resident of Millie, county of Norfolk,Commonwealth of Massachusetts, have invented an Improvement in theManufacture of Moistureproof Craped Papers, of which the. followingdescription, in connection with the accompanying drawings, is aspecification, like characters on the drawings representing like partsin each of the several views.

This invention relates to the: manufacture of paper for wrapping,packing, case lining and like uses that is craped or crinkled to imparta stretchable quality to the paper whereby its tendency to break underlocal strains and stresses is greatly reduced. More particularly theinvention relates Vto the manufacture of a craped wrapping or liningpaper that is also treated with waterproofing preparation capable ofrendering the paper wholly or largely moisture-proof. To this end, theinvention consists in an improved method of incorporating amoisture-resist- 'ing substance such as paraffin with the papersimultaneously with the craping and as an incident of the crapingoperation.

It has heretofore been proposed to adda proportionvof paraffin oil tothe hot bath in which the papier to be craped is immersed just prior tothe craping operating, but this has resulted in the taking up of toomuchoil and in an uneven manner by`the moving paper web, Aand the oilwould hence not d ry out and thesurface of the sheet be left with agreasy appearance,and also showing uneven distribution of the paralin. yll have found that by causing a slab or block of paraffin wax tovcontact with, and press against, the surface ofthe moving .web while itis hot and moist after immersion 1n the bath and just before it reachesthe craping station,l the sheet-is caused to take'up gust the rightamount of paraffin, e., in practice, about ten per cent., and with avery even distribution.

- Further than this, ll have found that this treatment of the hotm'oistened sheet with the parain wat results in a better crapiniifaction by the doctor, and that the crape eff ect produced has moreelasticity, and that the. paper so produced is even more pliable,conformable, and generally adapted for wrapping and like uses. than `isordinary craped paper,in addition to the water- Specication of LettersPatent. Pat'nted Sept, p3, 1921 1919. Serial No. 311,437.

proof property attained. The foregoing and' Fig. 2 is a diagrammaticside view thereof, and

Fig, 3 is a diagrammatic perspective further illustrating the workingparts.

10 indicates a bath tank into which the paper web W to 1be craped isdrawn from a supply roll R journaled on suitable supports 1l. The tank 10 may be equipped with any suitable means for heating the water orsolution therein, this being shown as steam pipes l2 in the bottom ofthe tank. The paper web is guided around rolls 13, 14 downward throughthe tank and lengthwise thereof so as to be immersed in the hot liquidfor the requisite-period. Thence it is directed around a smooth surfacedroll 15 preferably of steel as usual, and while clinging to this roll,engaged and removed therefrom by a doctor blade 16 in the usual inanner,this blade presenting a blunt edge which skufls back and imparts thewell known erinkled or craped effect in the paper as indicated at C, thecraped web being removed by suitable means (not shown). As shown, thedisposition of parts is such that the paper web engages around asubstantial angular extent of the smooth surfaced roll- 15, z'. e.,somewhat more than half the circumference thereof, and spaced apartpresser rolls 17,18 are provided to press upon the surface of the paperclinging to the roll 15. The presser roll 17 engages the paper shortlyafter it contacts with the roll 15 and presses the paper evenly anduniformly to the surface of the smooth roll 15 removing air pockets andalso pressing out excess moisture. Just beyond and above theroll 17 ismounted an inclined platform 19 presenting a smooth top srface extendingdown into proximity with the surface of the roll 15. This platform isadapted to receive a block or slab S of paraiiin wa'x` and the inclineof itssurface is such that the wax slab will slide down the saine intomoderate pressing contact with the surface of the paper on the Abeyondthe platform 19 and as shown directly above the roll 15. This rollpressing on the paper sheet further insures close .and even adherence tothe smooth surfaced roll andfacilitates the even distribution of the waXand the striking-in thereof into the pores and interstices of the paper.Thence the paper advances to thek doctor 16 where it is craped as usual.I preferably provide drip pans 20, 21 suitably located to catch anydrippings of the melted wax from the wax applying station or the doctor,these preventing any dripping back of the wax into the bath tank whichwould result in a deleterious effect from the taking up of suchdrippings by the web and causing an uneven application of the wax. Theslide platform 19 may be mounted at a suitable angle for the purposeshaving in mind the speed of the paper web, the hardness of the wax, andother considerations; in practice, I have found that an angle of aboutthirty degrees is suitable in most cases to cause proper contact of thewax slab with the` paper surface and results .in the melt-- ing andtaking up of the waxl in correct proportion vfor the results required.This showing of the mounting or holder for the slab as being an inclinedgravity platform is to be understood as merely illustrative andtypifying any suitable means for causing the wax slab to advanceautomatically so as to keep in continuous contact with the movingsurface of the paper web on the smooth surfaced roll. Therefore ingeneral, I am aware that the invention may be embodied in other specificforms without departing from the spirit or essential attributes thereof,and I desire the present embodiment to be considered in all respects asj illustrative and not restrictive, reference being had to the appendedclaims rather paper 1. The' combination with paper craping .apparatuscomprising a moistening tank and a craping roll and doctor, of means forapplying waterproofing substance to the paper consisting in a mountingfor a wax block constructed and arranged to cause continuous Contact ofthe wax block with 'the paper on said roll` just prior to the crapingthereof.

2. The combination withpaper craping apparatus comprising a moisteningtank and a craping roll and doctor, of means coperative with said rollfor pressing the evenly thereto, and means for mounting and holding ablock of wax or the like to engage and press continuously against thesurface of the paper on said roll just prior to the craping thereof.

3. The combination with paper craping apparatus including a smoothsurfaced crap- `ing roll and paper moistening means, of

means for mounting and holding a block of wax or the like to pressconstantly upon the surface of the paper on said roll just prior to thecraping thereof.

4. The combination with paper craping apparatus including a smoothsurfaced roll and moistening means, of an inclined platform adapted tohold a block of wax or the like to move thereon by gravity and engagecontinuously the surface of the paper web just prior to the -crapingthereof.

5. The herein describedl method which consists in first moistening andheating paper, then subjecting the paper surface while still hot toengagement with a wax mass in solid form, and then craping the paper.

In testimony whereof, I have signed my name to this specification.

lANDREW E. GURRIER.

